readShapePoints: Read points shape files into SpatialPointsDataFrame objects

Description Usage Arguments Value Author(s) See Also Examples

View source: R/SpatialPoints-methods.R

Description

The use of this function is deprecated and it is not being maintained. Use rgdal::readOGR() or sf::st_read() instead - both of these read the coordinate reference system from the input file, while this deprecated function does not.For writing, use rgdal::writeOGR() or sf::st_write() instead.

The readShapePoints reads data from a points shapefile into a SpatialPointsDataFrame object. The writePointsShape function writes data from a SpatialPointsDataFrame object to a shapefile. Both reading and writing can be carried out for 2D and 3D point coordinates. Note DBF file restrictions in write.dbf.

Usage

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readShapePoints(fn, proj4string = CRS(as.character(NA)), verbose = FALSE,
 repair=FALSE)
writePointsShape(x, fn, factor2char = TRUE, max_nchar=254)

Arguments

fn

shapefile layer name, when writing omitting the extensions *.shp, *.shx and *.dbf, which are added in the function

proj4string

Object of class CRS; holding a valid proj4 string

verbose

default FALSE - report type of shapefile and number of shapes

repair

default FALSE: some shapefiles provided by Geolytics Inc. have values of object sizes stored in the *.shx index file that are eight bytes too large, leading the function to try to read past the end of file. If repair=TRUE, an attempt is made to repair the internal values, permitting such files to be read.

x

a SpatialPointsDataFrame object

factor2char

logical, default TRUE, convert factor columns to character

max_nchar

default 254, may be set to a higher limit and passed through to the DBF writer, please see Details in write.dbf

Value

a SpatialPointsDataFrame object

Author(s)

Roger Bivand

See Also

write.dbf

Examples

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library(maptools)
xx <- readShapePoints(system.file("shapes/baltim.shp", package="maptools")[1])
plot(xx)
summary(xx)
xxx <- xx[xx$PRICE < 40,]
tmpfl <- paste(tempdir(), "xxpts", sep="/")
writePointsShape(xxx, tmpfl)
getinfo.shape(paste(tmpfl, ".shp", sep=""))
axx <- readShapePoints(tmpfl)
plot(axx, col="red", add=TRUE)
unlink(paste(tmpfl, ".*", sep=""))
xx <- readShapePoints(system.file("shapes/pointZ.shp", package="maptools")[1])
dimensions(xx)
plot(xx)
summary(xx)

Example output

Loading required package: sp
Checking rgeos availability: FALSE
 	Note: when rgeos is not available, polygon geometry 	computations in maptools depend on gpclib,
 	which has a restricted licence. It is disabled by default;
 	to enable gpclib, type gpclibPermit()
Warning message:
readShapePoints is deprecated; use rgdal::readOGR or sf::st_read 
Object of class SpatialPointsDataFrame
Coordinates:
            min   max
coords.x1 860.0 987.5
coords.x2 505.5 581.0
Is projected: NA 
proj4string : [NA]
Number of points: 211
Data attributes:
    STATION          PRICE            NROOM            DWELL       
 Min.   :  1.0   Min.   :  3.50   Min.   : 3.000   Min.   :0.0000  
 1st Qu.: 53.5   1st Qu.: 30.95   1st Qu.: 5.000   1st Qu.:0.0000  
 Median :106.0   Median : 40.00   Median : 5.000   Median :1.0000  
 Mean   :106.0   Mean   : 44.31   Mean   : 5.199   Mean   :0.5355  
 3rd Qu.:158.5   3rd Qu.: 53.75   3rd Qu.: 6.000   3rd Qu.:1.0000  
 Max.   :211.0   Max.   :165.00   Max.   :10.000   Max.   :1.0000  
     NBATH           PATIO            FIREPL             AC        
 Min.   :1.000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
 1st Qu.:1.000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
 Median :1.500   Median :0.0000   Median :0.0000   Median :0.0000  
 Mean   :1.573   Mean   :0.1469   Mean   :0.2417   Mean   :0.2417  
 3rd Qu.:2.000   3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:0.0000  
 Max.   :5.000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
     BMENT           NSTOR            GAR              AGE       
 Min.   :0.000   Min.   :1.000   Min.   :0.0000   Min.   :  0.0  
 1st Qu.:2.000   1st Qu.:2.000   1st Qu.:0.0000   1st Qu.: 20.0  
 Median :2.000   Median :2.000   Median :0.0000   Median : 25.0  
 Mean   :1.981   Mean   :1.905   Mean   :0.2512   Mean   : 30.1  
 3rd Qu.:3.000   3rd Qu.:2.000   3rd Qu.:0.0000   3rd Qu.: 40.0  
 Max.   :3.000   Max.   :3.000   Max.   :3.0000   Max.   :148.0  
     CITCOU           LOTSZ             SQFT             X        
 Min.   :0.0000   Min.   :  5.70   Min.   : 5.76   Min.   :860.0  
 1st Qu.:0.0000   1st Qu.: 20.76   1st Qu.:11.02   1st Qu.:889.0  
 Median :1.0000   Median : 56.25   Median :13.44   Median :910.0  
 Mean   :0.6066   Mean   : 72.28   Mean   :16.43   Mean   :911.6  
 3rd Qu.:1.0000   3rd Qu.: 84.32   3rd Qu.:19.94   3rd Qu.:933.5  
 Max.   :1.0000   Max.   :400.37   Max.   :47.61   Max.   :987.5  
       Y        
 Min.   :505.5  
 1st Qu.:528.8  
 Median :544.5  
 Mean   :544.2  
 3rd Qu.:559.0  
 Max.   :581.0  
Warning message:
writePointsShape is deprecated; use rgdal::writeOGR or sf::st_write 
Shapefile type: Point, (1), # of Shapes: 103
Warning message:
readShapePoints is deprecated; use rgdal::readOGR or sf::st_read 
Warning message:
readShapePoints is deprecated; use rgdal::readOGR or sf::st_read 
[1] 3
Object of class SpatialPointsDataFrame
Coordinates:
                   min         max
coords.x1  721627.3367  768477.042
coords.x2 5433514.5147 5507962.986
coords.x3     274.4738    1821.528
Is projected: NA 
proj4string : [NA]
Number of points: 400
Data attributes:
       Id         WTN          coords_x1        coords_x2      
 Min.   :0   Min.   :  186   Min.   :721627   Min.   :5433515  
 1st Qu.:0   1st Qu.:18974   1st Qu.:738257   1st Qu.:5448530  
 Median :0   Median :34510   Median :749857   Median :5455814  
 Mean   :0   Mean   :37679   Mean   :746783   Mean   :5461250  
 3rd Qu.:0   3rd Qu.:57886   3rd Qu.:752059   3rd Qu.:5472530  
 Max.   :0   Max.   :83171   Max.   :768477   Max.   :5507963  
   coords_x3     
 Min.   : 274.5  
 1st Qu.: 307.0  
 Median : 397.1  
 Mean   : 452.1  
 3rd Qu.: 481.1  
 Max.   :1821.5  

maptools documentation built on Sept. 7, 2021, 5:09 p.m.